U.S. patent number 8,433,081 [Application Number 12/398,586] was granted by the patent office on 2013-04-30 for bone conduction devices generating tangentially-directed mechanical force using a linearly moving mass.
This patent grant is currently assigned to Cochlear Limited. The grantee listed for this patent is John L. Parker. Invention is credited to John L. Parker.
United States Patent |
8,433,081 |
Parker |
April 30, 2013 |
Bone conduction devices generating tangentially-directed mechanical
force using a linearly moving mass
Abstract
A bone conduction device, comprising: a sound input element
configured to receive an acoustic sound signal; an electronics
module configured generate an electrical signal representing said
acoustic sound signal; and a transducer, comprising a mass
configured to move in a rotational direction, configured to
generate a vibrational force in a tangential direction with respect
to a recipient's bone.
Inventors: |
Parker; John L. (Roseville,
AU) |
Applicant: |
Name |
City |
State |
Country |
Type |
Parker; John L. |
Roseville |
N/A |
AU |
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Assignee: |
Cochlear Limited (Macquarie
University, NSW, AU)
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Family
ID: |
41117259 |
Appl.
No.: |
12/398,586 |
Filed: |
March 5, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090252353 A1 |
Oct 8, 2009 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61041185 |
Mar 31, 2008 |
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Current U.S.
Class: |
381/151; 607/57;
381/328; 381/173; 600/25; 381/312 |
Current CPC
Class: |
H04R
25/606 (20130101); H04R 25/70 (20130101); H04R
25/00 (20130101); A61M 5/14276 (20130101); A61M
2210/0662 (20130101); A61M 2205/05 (20130101); Y10T
29/49572 (20150115); H04R 2460/13 (20130101) |
Current International
Class: |
H04R
25/00 (20060101) |
Field of
Search: |
;381/150,151,173,312,328
;600/25 ;607/57 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0193634 |
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Dec 2001 |
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WO |
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03001845 |
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Jan 2003 |
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WO |
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Other References
Vermiglio et al., "A Measurement of Sound Level Perception when
using the Bone-Anchored Hearing Aid (BAHA) for Trans-Cranial
Stimulation of Individuals with Single-Side Deafness" House Ear
Institute. Advanced Hearing Science, International Hearing Aid
Research Conference. Aug. 2004 (22 pages). cited by
applicant.
|
Primary Examiner: Nguyen; Ha Tran T
Assistant Examiner: Chi; Suberr
Attorney, Agent or Firm: Kilpatrick, Townsend &
Stockton, LLP.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional
Patent Application 61/041,185; filed Mar. 31, 2008, which is hereby
incorporated by reference herein.
Claims
What is claimed is:
1. A bone conduction device configured to attach to a recipient's
bone, comprising: a sound input device configured to receive an
acoustic sound signal; an electronics module configured to generate
an electrical signal representing said acoustic sound signal; and a
transducer, comprising a mass, configured to generate a linear
vibrational force that is substantially tangential with respect to
a surface of the recipient's bone at a location at which the bone
conduction device is attached thereto.
2. The device of claim 1, wherein said transducer further comprises
one or more piezoelectric elements configured to generate said
vibrational force.
3. The device of claim 1, further comprising: an anchor coupled to
said transducer and fixedly secured to a recipient's skull,
configured to transfer said vibrational force to the skull.
4. The device of claim 3, wherein said transducer further comprises
a magnet configured to facilitate coupling said transducer to said
anchor.
5. The device of claim 3, wherein said transducer and said anchor
are coupled mechanically.
6. The device of claim 3, wherein said transducer is mechanically
coupled to a coupling configured to receive one end of said
anchor.
7. The device of claim 3, wherein said one end of said anchor is
fixedly attached to the recipient's skull.
8. The device of claim 7, wherein said anchor is configured to be
positioned at least partially in the recipient's skull and further
configured to osseointegrate with the recipient's skull over a
period of time.
9. The device of claim 7, further comprising a fixation plate
configured to securely attach to the recipient's skull, wherein
said anchor is configured to be coupled to said fixation plate.
10. The device of claim 9, wherein said plate is configured to
osseointegrate with the recipient's skull over a period of
time.
11. The device of claim 1, wherein the bone conduction device is
configured to be attached to a skull of the recipient behind an
outer ear of the recipient such that the vibrational force
generated by the transducer imparts a rotational force about the
recipient's neck.
12. A bone conduction device configured to attach to a recipient's
bone, comprising: a bone interface configured to extend into a
recipient's bone below a surface of the recipient's bone; and a
transducer in vibratory communication with the bone interface and
configured to generate a vibrational force in a direction that is
tangential with respect to the surface of the recipient's bone at a
location at which the bone conduction device is attached
thereto.
13. The device of claim 12, wherein said transducer comprises a
mass and one or more piezoelectric elements configured to generate
said vibrational force.
14. The device of claim 12, wherein the bone interface includes an
anchor that is configured to be fixedly secured to the recipient's
skull and transfer said vibrational force to the skull.
15. The device of claim 12, wherein: the transducer includes a mass
configured to rotate about an axis; and the transducer is
configured to apply an adjustment to at least one of a location,
relative to another component of the bone conduction device, of the
axis about which the mass rotates while the mass is rotating, or a
rotational velocity of the mass thereby producing the vibrational
force.
16. The device of claim 15, wherein the bone conduction device is
configured to exert a torque vibrational force as a result of the
adjustment.
17. The device of claim 15, wherein the bone conduction device is
configured to be attached to a skull of a recipient behind an outer
ear of the recipient such that the adjustment imparts a rotational
force about the recipient's neck.
18. The device of claim 12, wherein said transducer is configured
to generate a linear vibrational force in the direction that is
tangential with respect to the surface of the recipient's bone.
Description
BACKGROUND
1. Field of the Invention
The present invention relates generally to prosthetic hearing
devices, and more particularly, to a bone conduction hearing
devices generating stimulation via tangentially-directed
vibrational force with respect to a surface of the recipient's
bone.
2. Related Art
There are three basic types of hearing loss: sensorineural,
conductive, and mixed hearing losses. Sensorineural hearing loss
results from damage to the inner ear or to the nerve pathways from
the inner ear to the brain. The majority of human sensorineural
hearing loss is caused by abnormalities or damage to the hair cells
in the cochlea. Hair cells in the cochlea are the sensory receptors
that transduce sound to nerve impulses. Acoustic hearing aids may
be appropriate for those who suffer from mild to moderate
sensorineural hearing loss. In cases of severe or profound
sensorineural hearing loss, a cochlear implant may be the
appropriate choice. Cochlear implants bypass the hair cells in the
cochlea and directly stimulate the auditory nerve fibers in the
cochlea by an electrode array that is implanted in the cochlea.
Simulation of the auditory nerve fibers creates the sensation of
hearing in the recipient.
Conductive hearing loss occurs when there is a problem with the
conduction of sound from the external or middle ear to the inner
ear. This type of hearing loss may be caused by anything that
impedes the motion of the ossicles, the three bones of the middle
ear that conduct sound to the cochlea. It may also be caused by a
failure of the eardrum to vibrate in response to sound or fluid in
the middle ear. Conductive hearing loss may be treated by acoustic
hearing aids, middle ear implants, and the like.
Still other individuals suffer from mixed hearing losses, that is,
conductive hearing loss in conjunction with sensorineural hearing.
In other words, there may be damage in both the outer or middle ear
and the inner ear (cochlea) or auditory nerve.
While many individuals suffering from conductive hearing loss often
use acoustic hearing aids, such hearing aids may not be suitable
for all individuals, such as those suffering from chronic ear
infections or from single-sided deafness. An alternative treatment
is the use of bone conduction hearing aids, or simply conduction
devices herein.
Bone conduction hearing aids utilize the bones of an individual's
bone to transmit acoustic signals to the cochlea. Generally, most
bone conduction hearing aids function by converting a received
sound signal into vibration. This vibration is then transferred to
the bone structure of the bone, in one particular embodiment the
skull. This skull vibration results in motion of the fluid of the
cochlea, thereby stimulating the cochlear hair cells and causing
the perception of sound in the recipient.
Bone conduction devices may be attached to a titanium implant
implanted in a recipient's bone, via an external abutment. In one
particular embodiment of the present invention, the titanium
implant is surgically implanted into the part of the skull bone
that is behind the ear and allowed to naturally integrate with the
skull bone over time. The bone conduction device is coupled to the
titanium implant via the external abutment. Vibrations from the
bone conduction device are then transmitted to the skull through
the external abutment and the titanium implant to stimulate nerve
fibers of the inner ear of the recipient.
Some bone conduction devices produce sound perception by applying a
vibrational force directly to the recipient's bone, which is
communicated through the bone eventually to the cochlea where the
fluids contained therein are vibrated. In some devices, the
vibrational force is directed towards the recipient's bone
perpendicularly with respect to the surface of the recipient's
bone. In such devices, the angle between the surface of the
recipient's bone and the direction of the vibrational force is as
close to 90 degrees as possible in order to ensure the most
efficient transfer of vibrational force to the recipient's bone as
possible. As noted earlier, the transferred vibrational force is
conducted through the bone to the recipient's cochlea, causing
motion of the cochlear fluid, thereby producing sound perception.
It may be possible to cause that movement of cochlear fluid to
produce the sound perception in other ways without directly
applying and communicating a vibrating vibrational force to the
recipient's bone.
SUMMARY
In one aspect of the present invention, another bone conduction
device is provided. The bone conduction device comprises: a sound
input device configured to receive an acoustic sound signal; an
electronics module configured generate an electrical signal
representing said acoustic sound signal; and a transducer,
comprising a mass, configured to vibrate said mass in a linear
direction so as to generate a vibrational force tangential with
respect to a recipient's skull so as to vibrate a mass in a
substantially linear direction.
In another aspect of the present invention, a method rehabilitating
the hearing of a recipient with a bone conduction device is
provided. The method comprises rehabilitating the hearing of a
recipient with a bone conduction device having an anchor,
comprising: forming a mechanical coupling between the bone
conduction device and the recipient's bone via the anchor;
receiving an electrical signal representative of an acoustic sound
signal; generating a vibrational force, using a rotating mass,
representative of the received electrical signal, wherein the
vibrational force is directed in a tangential direction with
respect to the recipient's bone; and delivering said vibrational
forces to the recipient's bone via the formed coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative embodiments of the present invention are described
herein with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a bone-rotating bone conduction
device implanted behind a recipient's ear;
FIG. 2A is a high-level functional block diagram of a bone-rotating
bone conduction device, such as the device of FIG. 1;
FIG. 2B is detailed functional block diagram of the bone-rotating
bone conduction device illustrated in FIG. 2A;
FIG. 3 is a flowchart illustrating the conversion of an input sound
into movement of cochlear fluid in accordance with embodiments of
the present invention;
FIG. 4A is a cross-sectional view of a bone-rotating bone
conduction device in accordance with embodiments of the present
invention;
FIG. 4B is a perspective view of components of a bone-rotating bone
conduction device in accordance with embodiments of the present
invention;
FIG. 4C is a perspective view of other components of a
bone-rotating bone conduction device in accordance with embodiments
of the present invention;
FIG. 5A is a perspective view of a transducer module of a bone
rotating bone conduction device in accordance with embodiments of
the present invention;
FIG. 5B is a first cross-sectional view of the transducer module of
the bone conduction device illustrated in FIG. 5A in accordance
with embodiments of the present invention;
FIG. 5C is a second cross-sectional view of the transducer module
of the bone conduction device illustrated in FIG. 5A in accordance
with embodiments of the present invention; and
FIG. 6 is a cross-sectional view of a bone-rotating bone conduction
device in accordance with other embodiments of the present
invention.
DETAILED DESCRIPTION
Embodiments of the present invention are generally directed to a
bone conduction device for converting a received acoustic sound
signal into a vibrational force that is generated in a tangential
direction with respect to the surface of the recipient's bone,
which ultimately produces sound perception by the recipient. The
tangentially directed vibrational force generated by embodiments of
the present invention causes rotation of the skull about the neck
and is conducted to the cochlea of the recipient. The conducted
force acts on the cochlea to cause motion of the cochlear fluid
contained therein, causing the hair cells in the cochlea to be
activated to produce sound perception by the recipient.
The bone conduction device receives the acoustic sound signal and
generates an electrical signal representing the acoustic sound
signal. The bone conduction device includes a transducer which
converts the electrical signal into motion of a mass component so
as to generate the vibrational force directed in a tangential
direction with respect to the surface of the recipient's bone,
causing rotation of the recipient's skull about the neck. In
certain embodiments of the present invention, the transducer has a
flywheel component which rotates about a fixed axis. In those
embodiments, one or more coils positioned around the circumference
of, and separate from, the flywheel component may be energized so
as to pull or push the spinning flywheel from its rotation axis,
thereby generating a vibrational force that is directed in a
tangential direction with respect to the recipient's skull, to
cause it to rotate about the recipient's neck.
In some embodiments, the transducer module may be outside the
recipient's skin, attached to a percutaneous anchor system. In
other embodiments, the system may comprise the transducer module
embedded or implanted under the recipient's skin and further
comprise communication components configured to communicate with
the implanted transducer module to provide instructions and
possibly even power to the implanted transducer.
In various embodiments of the present invention, the transducer may
comprise a piezoelectric element that deforms in response to
application of the electrical signal thereto, thereby generating
vibrational forces. The amount of deformation of a piezoelectric
element in response to an applied electrical signal depends on
material properties of the element, orientation of the electric
field with respect to the polarization direction of the element,
geometry of the element, etc.
FIG. 1 is a perspective view of embodiments of a bone conduction
device 100 in which embodiments of the present invention may be
advantageously implemented. In a fully functional human hearing
anatomy, outer ear 101 comprises an auricle 105 and an ear canal
106. A sound wave or acoustic pressure 107 is collected by auricle
105 and channeled into and through ear canal 106. Disposed across
the distal end of ear canal 106 is a tympanic membrane 104 which
vibrates in response to acoustic wave 107. This vibration is
coupled to oval window or fenestra ovalis 110 through three bones
of middle ear 102, collectively referred to as the ossicles 111 and
comprising the malleus 112, the incus 113 and the stapes 114. Bones
112, 113 and 114 of middle ear 102 serve to filter and amplify
acoustic wave 107, causing oval window 110 to articulate, or
vibrate. Such vibration sets up waves of fluid motion within
cochlea 115. Such fluid motion, in turn, activates tiny hair cells
(not shown) that line the inside of cochlea 115. Activation of the
hair cells causes appropriate nerve impulses to be transferred
through the spiral ganglion cells and auditory nerve 116 to the
brain (not shown), where they are perceived as sound.
FIG. 1 also illustrates the positioning of one embodiment of the
present invention bone conduction device 100 relative to outer ear
101, middle ear 102 and inner ear 103 of a recipient of device 100.
As shown, bone conduction device 100 may be positioned behind outer
ear 101 of the recipient. In the embodiment illustrated in FIG. 1,
bone conduction device 100 is an externally fitted embodiment of
the present invention and comprises a housing 125 having a
microphone (not shown) positioned therein or thereon. Housing 125
is coupled to the body of the recipient via coupling 140 and an
anchor system 162. As described below, bone conduction device 100
may comprise a sound processor, a transducer, transducer drive
components and/or various other electronic circuits/devices. In
accordance with embodiments of the present invention, anchor system
162 may be implanted in the recipient. As described below, anchor
system 162 may be fixed to bone 136 and may extend from bone 136
through muscle 134, fat 128 and skin 132 so that coupling 140 may
be coupled to the anchor system.
A functional block diagram of one embodiment of bone conduction
100, referred to as bone conduction device 200, is shown in FIG.
2A. In the illustrated embodiment, a sound wave 207 is received by
a sound input element 202. In some embodiments, sound input element
202 is a microphone configured to receive sound wave 207, and to
convert sound wave 207 into an electrical signal 222. As described
below, in other embodiments, sound wave 207 may be received by
sound input element 202 as an electrical signal.
As shown in FIG. 2A, electrical signal 222 is output by sound input
element 202 to an electronics module 204. Electronics module 204 is
configured to convert electrical signal 222 into an adjusted
electrical signal 224. As described below in more detail,
electronics module 204 may include a sound processor, control
electronics, transducer drive components, and a variety of other
elements.
As illustrated in FIG. 2A, transducer module 206 receives adjusted
electrical signal 224 and generates a vibrational output force that
is directed in a tangential direction with respect to the
recipient's bone. The tangentially directed vibrational force is
delivered to the skull of the recipient via coupling 140, shown in
FIG. 2A as a part of anchor system 208, that is coupled to bone
conduction device 200. Delivery of this output force causes the
recipient's skull to rotate about the recipient's neck and causes
movement or waves of the cochlear fluid, resulting in activating
the hair cells in the cochlea to produce sound perception.
FIG. 2A also illustrates a power module 210. Power module 210
provides electrical power to one or more components of bone
conduction device 200. For ease of illustration, power module 210
has been shown connected only to interface module 212 and
electronics module 204. However, it should be appreciated that
power module 210 may be used to supply power to any electrically
powered circuits/components of bone conduction device 200.
Bone conduction device 200 further includes an interface module 212
that allows the recipient to interact with device 200. For example,
interface module 212 may allow the recipient to adjust the volume,
alter the speech processing strategies, power on/off the device,
etc. Interface module 212 communicates with electronics module 204
via signal line 228.
In the embodiment illustrated in FIG. 2A, sound pickup device 202,
electronics module 204, transducer module 206, power module 210 and
interface module 212 have all been shown as integrated in a single
housing, referred to as housing 225. However, it should be
appreciated that in certain embodiments of the present invention,
one or more of the illustrated components may be housed in separate
or different housings, one or more of which may be surgically
implanted under the recipient's skin. Furthermore, the implanted
components may be embedded at least partially within the
recipient's bone or otherwise fixed to the bone so as to prevent
movement with respect to the bone. Similarly, it should also be
appreciated that in such embodiments, direct connections between
the various modules and devices are not necessary and that the
components may communicate, for example, via wireless connections.
Also, where transducer module 206 is outside the recipient's skin,
the movement may be communicated via anchor system 208 to the
recipient's skull so as to cause the skull to rotate about the
recipient's neck. Where transducer module 206 is among the
components implanted beneath the recipient's skin, transducer
module 206 may be fixed to the recipient's skull through a variety
of means so as to communicate the vibrational force to the
recipient's skull to cause the skull to rotate about the
recipient's neck.
In embodiments of the present invention, transducer module 206 may
be one of many types and configurations of transducers, now known
or later developed. In one embodiment of the present invention,
transducer module 206 may comprise a piezoelectric element which is
configured to deform in response to the application of electrical
signal 224. Piezoelectric elements that may be used in embodiments
of the present invention may comprise, for example, piezoelectric
crystals, piezoelectric ceramics, or some other material exhibiting
a deformation in response to an applied electrical signal.
Exemplary piezoelectric crystals include quartz (SiO2), Berlinite
(AlPO4), Gallium orthophosphate (GaPO4) and Tourmaline. Exemplary
piezoelectric ceramics include barium titanate (BaTiO30), lead
zirconate titanate (PZT), or zirconium (Zr).
Some piezoelectric materials, such as barium titanate and PZT, are
polarized materials. When an electric field is applied across these
materials, the polarized molecules align themselves with the
electric field, resulting in induced dipoles within the molecular
or crystal structure of the material. This alignment of molecules
causes the deformation of the material.
In other embodiments of the present invention, other types of
transducers may be used. For example, various motors configured to
operate in response to electrical signal 224 may be used.
In one embodiment of the present invention, transducer module 206
generates an output force that is directed tangentially with
respect to the surface of the recipient's bone. This tangentially
directed vibrational force causes rotation of the recipient's skull
about the neck, to produce movement of the cochlea fluid so that a
sound may be perceived by the recipient. As noted above, in certain
embodiments, bone conduction device 200 delivers the output force
to the skull of the recipient via an anchor system 208. In one
embodiment of the present invention, anchor system 208 comprises a
coupling 260 mechanically couples to an implanted anchor 262, as
illustrated in FIG. 2B. Vibration from transducer module 206 is
provided to anchor system 208 through housing 225.
In certain embodiments of the present invention, electronics module
204 includes a printed circuit board (PCB) to electrically connect
and mechanically support the components of electronics module 204.
Sound input element 202 may comprise one or more microphones (not
shown) and is attached to the PCB.
FIG. 2B provides a more detailed view of bone conduction device 200
of FIG. 2A. In the embodiment illustrated, electronics module 204
comprises a sound processor 240, transducer drive components 242
and control electronics 246. As explained above, in certain
embodiments sound input element 202 comprises a microphone
configured to convert a received acoustic signal into electrical
signal 222. In other embodiments, as detailed below, sound input
element 202 receives sound wave 207 as an electrical signal.
In embodiments of the present invention, electrical signal 222 is
output from sound input element 202 to sound processor 240. Sound
processor 240 uses one or more of a plurality of techniques to
selectively process, amplify and/or filter electrical signal 222 to
generate a processed signal 226. In certain embodiments, sound
processor 240 may comprise substantially the same sound processor
as is used in an air conduction hearing aid. In further
embodiments, sound processor 240 comprises a digital signal
processor.
Processed signal 226 is provided to transducer drive components
242. Transducer drive components 242 output a drive signal 224, to
transducer module 206. Based on drive signal 224, transducer module
206 provides the output force to the skull of the recipient.
For ease of description the electrical signal supplied by
transducer drive components 242 to transducer module 206 has been
referred to as drive signal 224. However, it should be appreciated
that processed signal 224 may comprise an unmodified version of
processed signal 226.
As noted above, in one embodiment of the present invention,
transducer module 206 generates an output force to the skull that
is tangentially directed with respect to the recipient's skull. The
generated vibrational force is conducted via anchor system 208 in
this embodiment. As shown in FIG. 2B, in one embodiment of the
present invention, anchor system 208 comprises a housing coupling
260 and an implanted anchor 262. In this embodiment, housing
coupling 260 is used to couple housing 225 to implanted anchor 262.
Coupling 260 may be mechanically coupled to transducer 206 or
housing 225 such that vibrational forces from transducer 206 or
housing 225 will be mechanically transferred to coupling 260. For
example, in certain embodiments, coupling 260 is mechanically
coupled to transducer 206 and vibration is received directly
therefrom. In other embodiments, coupling 260 is mechanically
coupled to housing 225 and vibration is applied from transducer 206
through housing 225 to coupling 260. Since, according to this
embodiment of the present invention, coupling 260 is mechanically
coupled to anchor 262, anchor 262 also vibrates in the tangential
direction as described above. The vibration of anchor 262 will then
cause the recipient's skull to vibrate, rotating the recipient's
skull around the recipient's neck and cause the movement of
cochlear fluid to be set in a particular motion, producing sound
perceptions as described earlier.
In addition to the mechanical coupling between coupling 260 and
anchor 262 described above, certain embodiments of the present
invention may also utilize other types of couplings between the
recipient's skull and transducer 206. For example, anchor 262 may
be magnetically coupled to transducer 206 such that the vibrational
forces generated by transducer 206 are transmitted magnetically to
anchor 262. Furthermore, although transducer 206 and anchor 262
have been presently described as two separate components, it is to
be understood that transducer 206 and anchor 262 as described
herein may be manufactured as a single or unitary component or
manufactured separately and permanently joined together.
Bone conduction device 200 may further comprise an interface module
212. Interface module 212 includes one or more components that
allow the recipient to provide inputs to, or receive information
from, elements of bone conduction device 200.
As shown, control electronics 246 may be connected to one or more
of interface module 212, sound pickup device 202, sound processor
240 and/or transducer drive components 242. In embodiments of the
present invention, based on inputs received at interface module
212, control electronics 246 may provide instructions to, or
request information from, other components of bone conduction
device 200. In certain embodiments, in the absence of user inputs,
control electronics 246 control the operation of bone conduction
device 200.
FIG. 3 illustrates the conversion of an input acoustic sound signal
into a vibrational force for delivery to the recipient's skull in
accordance with embodiments of bone conduction device 200. At block
302, bone conduction device 200 receives an acoustic sound signal.
In certain embodiments, the acoustic sound signal is received via
microphones 202. In other embodiments, the input sound is received
via an electrical input. In still other embodiments, a telecoil
integrated in, or connected to, bone conduction device 200 may be
used to receive the acoustic sound signal.
At block 304, the acoustic sound signal received by bone conduction
device 200 is processed by the speech processor in electronics
module 204. As explained above, the speech processor may be similar
to speech processors used in acoustic hearing aids. In such
embodiments, speech processor may selectively amplify, filter
and/or modify acoustic sound signal. For example, speech processor
may be used to eliminate background or other unwanted noise signals
received by bone conduction device 200.
At block 306, the processed sound signal is provided to transducer
module 206 as an electrical signal. At block 308, transducer module
206 converts the electrical signal into a vibrational force
configured to be delivered to the recipient's skull via anchor
system 208 so as to illicit a hearing perception of the acoustic
sound signal.
FIG. 4A illustrates one embodiment of the bone conduction device
400 of the present invention. In the illustrated embodiment,
coupling 460 is shown connected to anchor 462. Coupling 460 is
configured to deliver the vibrational force, generated tangentially
(shown as arrows 401) with respect to the surface of the
recipient's skull, from transducer 406 in housing 425 to the
recipient's skull 136. The tangentially directed vibrational force
acts on the recipient's skull 136 in a way that the recipient's
skull is caused to rotate about the recipient's neck. As will be
known to persons having skill in the relevant art, the amount of
force necessary to cause rotation of the recipient's skull about
the recipient's neck will be different and substantially less than
the amount of force necessary to cause the recipient's skull to
move in a non-rotating side-to-side or up-and-down manner.
Anchor 462 may be attached to recipient's skull 136 in a variety of
ways. For example, as illustrated in FIG. 4A, anchor 462 may have a
threaded portion 468 at one end which is to be positioned within or
adjacent to recipient's skull 136. A corresponding socket 466 may
have corresponding threads to receive the threaded portion 468 such
that anchor 462 may be screwed into socket 466 to achieve a secure
fixation of anchor 462 in recipient's skull 136. Alternatively, in
one embodiment, anchor 462 may not have a threaded socket as
described above but may instead be screwed directly into
correspondingly shaped holes (not shown) formed in recipient's
skull 136, wherein the threaded end 468 may have releasable
compounds which facilitate in the formation of new bone to surround
and securely fix anchor 462 in recipient's skull 136. Other method
of securing anchor 462 in recipient's skull 136, now known or later
developed, will be obvious to persons having skill in the art and
are considered a part of the present invention.
FIGS. 4B and 4C illustrate in more detail coupling 460 and anchor
462, respectively. As shown, coupling 460 is configured to receive
a specifically shaped or configured connection end 470 of anchor
462, shown in FIG. 4C. In the embodiment illustrated in FIG. 4B,
latch 472 may be operated to release anchor 462 that has been
secured within coupling 460 via connection end 470. In other
embodiments of the present invention, other securing and release
mechanisms may be used, such as fixation screws which may be
screwed in and out to secure and release anchor 462 in coupling
460. Other mechanisms, now known or later developed, will be
obvious to person of skill in the art and are considered a part of
the present invention.
Also shown in FIGS. 4A and 4C is a ring 464 which is configured to
be positioned on the surface of recipient's skin 132 so as to
provide a protective shield at the point where anchor 462 emerge
through recipient's skin 132. Ring 464 may be made of a flexible
material. Ring 464 may also have at least its bottom surface
adhered to recipient's skin 132. Furthermore, any gap or space
between the hollow center of ring 464 and anchor 462 may be sealed
so as to prevent air or moisture from entering or exiting through
the opening in recipient's skin 132. By providing ring 464 with a
bottom surface adhered to the recipient's skin, and by further
sealing any gaps which may otherwise exist between ring 464 and
anchor 462, it is possible for the anchor of the present invention
to operate over extended periods of time with a greatly reduced
risk of liquids and matter entering or leaving the recipient's
body, thus reducing various health risks such as infection.
Although a relatively simple ring 462 has been described above, it
should be understood that more extensive configurations for sealing
and securing the recipient's body at the entry point for anchor 462
into the recipient's body may be used in conjunction with
embodiments of the present invention.
For the sake of explanation, FIG. 5A illustrates transducer 406,
referred to as transducer 506, separately from the various other
components of the bone conduction device of the present invention,
as described above. In certain embodiments of the present
invention, transducer 506 comprises a mass which, when vibrated,
moves linearly in a tangential direction with respect to the
recipient's skull, thus producing vibrational force that is
tangentially directed with respect to the recipient's skull.
In other embodiments of the present invention, the tangentially
directed vibrational force is generated by a non-linearly moving
mass. FIG. 5B illustrates a first cross-section of the transducer
506 illustrated in FIG. 5A. In the embodiment illustrated, a
transducer control circuit 586 and a transducer power module 588 is
shown. The embodiment shown in FIGS. 5A-5C may be suitable for
implantation in a recipient's skull or embedded under the
recipient's skin.
FIG. 5C illustrate a second cross-section of transducer 506, in
which a flywheel 592 rotates about a spindle 594 within transducer
506. One or more flywheel magnets and coils 596A-596D (collectively
referred to herein as flywheel magnets/coils 596) are disposed
around the circumference of flywheel 592. After flywheel 592 has
been put in rotational motion, electrical signal 224 energizes
flywheel magnets/coils 596, causing flywheel 592 to shift from the
original spin-axis extending longitudinally through spindle 594.
the magnets/coils 596 are energized according to the electrical
signal representing the audio signal received. This shift by
flywheel 592 from its original spin-axis will produce a torque
vibrational force which is exerted on transducer 506, which then
communicates that force to the recipient's skull in the manner
described above. The vibrational force will cause the recipient's
skull to rotate about the recipient's neck and produce motion in
the cochlear fluid, thereby producing sound perception as described
above. In one embodiment of the present invention, the vibrational
force is generated by the flywheel by rapidly changing or
regulating the speed of the flywheel. In other embodiments of the
present invention, the vibrational force is generated by the
flywheel as its spin-axis is shifted or interrupted as described
above. It is to be understood that other techniques for using a
flywheel mechanically coupled to the recipient's bone to generate a
vibrational force directed tangentially with respect to the
recipient's bone are considered a part of the present
invention.
FIG. 6 illustrate another embodiment of the present invention in
which bone conduction device 100, referred to as bone conduction
device 600, comprises an external portion and an implanted portion.
In bone conduction device 600, the external portion comprises
external housing 661, external communication component 660, and
cable 663. Cable 663 may comprise a plurality of leads or cables or
optical fibers, and is coupled at one end to housing 661 and
external communication component 660 and to, for example, a sound
processor (not shown) or a power module (not shown) at the other
end. External housing 661 may comprise a securing mechanism (not
shown) such as a fixation magnet which magnetically couples to the
recipient or to a corresponding fixation magnet (not shown) that is
implanted or embedded in the recipient.
External communication component 660 may comprise a communication
coil (not shown) which may be configured to at least transmit
electrical signal to a receiving component 662 which may comprise
an antenna configured to receive the electrical signal transmitted
by external communication component 660. Receiving component 662
provides the received electrical signal to various circuits within
implanted housing 625, including transducer module 606, for further
processing and for use in generating tangentially directed
vibrational forces as described in conjunction with other
embodiments of the present invention.
In the embodiment illustrated in FIG. 6, the implanted portion also
comprises a fixation plate 664 and fixation screws 666A and 666B
(collectively referred to as fixation screws 666). As shown,
fixation plate 664 is coupled to the recipient's skull by fixation
screws 666 which securely retains plate 664 against the recipient's
skull. Implanted housing 625 is configured to be coupled to
fixation plate 664. Housing 625 and plate 664 may be configured so
that housing 625 does not become integrated or otherwise
permanently attached the recipient's skull 136 or other tissue.
Instead, housing 625 is configured to be coupled to fixation plate
664 in such a manner that it can be removed and replaced with
relative ease. For example, clips, screws or compression fit
mechanisms may be used to secure housing 625 to fixation plate 664.
As described previously in conjunction with other embodiments of
the present invention, bone conduction device 600 is used to
generate vibrational force in a tangential direction with respect
to the recipient's skull such that the recipient's skull is caused
to rotate about the recipient's neck and such that the motion
causes the recipient's cochlear fluid to be set in a particular
motion at audio frequencies, thereby producing sound perception by
the recipient. Further features of embodiments of the present
invention may be found in U.S. Provisional Patent Application
61/041,185, filed Mar. 31, 2008, which is hereby incorporated by
reference herein.
While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not limitation. It will be
apparent to persons skilled in the relevant art that various
changes in form and detail can be made therein without departing
from the spirit and scope of the invention. Thus, the breadth and
scope of the present invention should not be limited by any of the
above-described exemplary embodiments, but should be defined only
in accordance with the following claims and their equivalents. All
patents and publications discussed herein are incorporated in their
entirety by reference thereto.
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